Tool lift for an agricultural implement



g- 1950 F. N. SHARP TOOL LIFT FOR AN AGRICULTURAL IMPLEMENT Filed April 16, 1947 k UFm H mm 5 INVENTOR FRED N. SHARP Patented Aug. 8, 1950 UNITED STATES PATENT OFFICE TOOL LIFT FOR AN AGRICULTURAL IMPLEMENT 8 Claims. 1

This invention relates generally to a wheeled tool lift for a,power driven, walk behind agricultural implement and particularly to an improved type thereof which automatically provides for controlled engagement and disengagement of ground working tools with the ground.

There are known to exist a variety of tool lifts especially adapted to use with the conventional, small, garden type, tractor-cultivator. However, those tool lifts presently in known use require direct manual operation during at least some part of their operating cycle of raising and lowering the cultivating tool. Persons familiar with the handling of said conventional, small, garden type, tractor-cultivators are acquainted with the fact that an operator usually has both hands fully occupied in steering and controlling the said tractor-cultivator at about that time when the position of the tool lift needs changing. This situation occurs particularly as the cultivator is to be turned around at the end of a row.

Consequently, there is a recognized need for a completely automatic, tool lift adapted to use with said small tractor-cultivators of the walk behind type.

Accordingly, a major object of this invention is to provide an improved, wheeled tool lift for said conventional, small, garden type tractor-cultivator, which tool lift operates completely automatically with respect to said tractor-cultivator.

A further object of this invention is to provide a tool lift as aforesaid which automatically sets and resets itself in positions with respect to the chassis of said tractor-cultivator whereby the said cultivating tool will be positively and automatically held in a plurality of adjustably predetermined positions with respect to the surface of the ground.

A further object of this invention is to provide a tool lift as aforesaid which requires no direct manual operation.

A further object of this invention is to provide a tool lift as aforesaid which is simple and economical to produce.

A further object of this invention is to pro- In order to meet those objects and purposes heretofore mentioned, as well as others incidental thereto and associated therewith, I have conceivedan improved wheeled tool lift having a bracket for suitable, adjustable attachment of the tool lift to the chassis of the said tractor-cultivator and slidable support of a wheel standard, to which the wheel of said wheeled tool lift is secured at its lower extremity. Said bracket and said wheel standard are provided with means including a cammed pawl, whereby said wheel may be automatically held at certain positions with respect to said tractor-cultivator chassis, as desired and/or as required.

For a preferred embodiment of the invention, herein described, attention is directed to the drawings in which:

Figure 1 is a side elevationview of a conventional, garden type tractor-cultivator equipped with the automatic tool lift to which this invention relates.

Figure 2 is a side elevation view of the said automatic, wheeled tool lift, and includes a, fragment of the tractor-cultivator chassis at the point where said tool lift engages said chassis.

Figure 3 is an end view of said automatic, wheeled tool lift including said fragment of the said tractor-cultivator chassis.

Figure 4 is a side view of said tool lift with the wheel standard in the extended position.

Figure 5 is a fragmentary side view of a tool lift showing an alternate bracket and cammed pawl.

Figure 6 is a fragmentary side view of the alternate tool lift, shown in Figure 5, showing the wheel standard in extended position.

Figure '7 is a cross-sectional view of Figure 2 taken along the line VII--VII.

A conventional, small, garden type, walk behind tractor-cultivator, including a preferred embodiment of the tool lift comprising the invention, is shown in Figure 1, for purposes of illustration only, as having a chassis or frame ll] which may be fabricated from any type of suitable material, such as channels welded together. Said chassis it] may be supported by a pair of any convenient, conventional tractor wheels H and may in turn support upon one end thereof a suitable driving means such as, for example, an internal combustion engine 12 for the purpose of driving one or both of said wheels H by any appropriate means not shown. That end of said chassis, remote from the end supporting said engine, will advantageously support an appropriate cultivating tool l3 in any convenient manner.

The automatic tool lift [5 is preferably but not necessarily supported, adjustably, upon one of the longitudinal members 551 of said chassis between or behind said wheels ll and said cultivating "tool 13 :by means described hereinafter. A pair of handle bars l4 issuitably secured to said chassis in in the vicinity of that point where said chassis is supported upon said wheels 3 l, which point is advantageouslyapproximately the center of gravity of the entire device.

It will be understood thatyinsofar as :this particular embodiment of the invention isconcerned, the exact structure and type of said tractorcultivator, with which the said wheeled :teollift is used, is not limited, provided only that it has suitable means whereto the tool lift bracket 95 of said tool lift [5 may be secured, such as the :channel iron chassis "I ll.

As .shown more clearly in Fignres'2, 3 and a, the said 1t0o1=lift bracket 1-6 is comprised of a pair of -central;plates -2ll'and 2;! ,each of which-has a slide support member 22 and .23 respectively extending upwardly-therefrom and integral therewith or welded, or otherwise fastened thereto as convenient, These slide support members are substantially .longerthan wide and as here shown .are integral at their lower ends with their respective central plates. Said central ,platesand ,their respectively connected slide support anem- V ,bersmaybe fabricated fromany suitable material, such as sheet metal, provided that such material isof sufficient strength to withstandthe @stresses to which said :tool lift bracket will be slide support member .22, which projects .vertically from said central plate 2!! in line with said vertical guide groove 24, contains a longitudinally disposed centrally located guide slot v25 which extends +1 DIOXimately from the junction point between saidcentralplate and said slide support member to a point spaced from the free extrem- ;ity 26 ofsaidslide support member.

The longitudinal or vertical edges 2! of said slide support member 22 may be advantageously flanged outwardly thereby imparting additional strength to said'slide support member 22,'as shown in Figure '7.

As shown in Figure 4,131'18 slide support member 23 extends vertically from, and is preferably an integral part of, the central plate 25 in substantially the same "manner as said slide support member :22 is associated with said central plate 20. The slide support members being advantageously mirror images of each other, the support member 123 contains a guide slot '28 which is substantially opposite to, and aligned with, said slot 25 of saidsupport member 22 when the :said central plate 21, is approximately superimposed as illustrated in Figures 2 and :4, upon saidsupport plate :26]. The longitudinal or vertical edges 2d of said support member 23 may also be flanged outwardly for :additional strength ithereof, as-shown in Figure '7.

'The central plate 2;! is preferably secured to the other central plate 2.3 by any suitable means,

such as riveting, welding or brazing, so that said slide support members 22 and 23 will be parallel and opposite each other, and the said flanges 21 and 29, respectively, will extend away from each other, as shown in Figure '7. A passageway 35 will be defined by said vertical guide groove 24 andtsaid central plate2l "for slidable reception of the said areciprocable .wheel standard .38, which may be fabricated from any type of suitable material, such as bar stock. Said wheel standard may be attached at its lower end to the stem 32 of .a conventional wheel fork 33 by any suitable means, such as welding.

Near the .upper end of said wheel standard there is provided .a bolt opening 34, which is aligned with said slots 25 and 28 when said bracket i5 is operably engaged by said wheel standard as. A suitable bolt 35, which slidably extends through both of the said slots 25 and 28 and the bolt opening not only restricts the vertical, reoiprocable motion of said :wheel standard 3'0 within said bracket ["5 to the extent of said slots, but also provides lateral guidance therefor. l

A stop notch :36 is provided =inan edge of said Wheel standardsfl for engagement by the pointed lower extremity 37 of the cammed pawl 38 which is rotatably supported at its .upper extremityupon a p-ivot2bolt/39. Said stop notch is advantageously near to the upper extremity of said wheel standard, however, it may be at any point between said-extremities of said wheel standard as required or desired. The cammed pawl :38 has along one edge a :cam surface 40 whose detailed "shape and purpose will be described hereinafter.

Said cammed pawl 38 may be :of anysuitable material, but is :preferably fabricated from steel plate-of suflicientl less thickness than the normal distance between said slide support members22zand 2.31to effect easy passage of said pawl therebetween. Said pivot bolt 39 is received .through suitable openings in the slide support members {22 and 23 near their upper ends so that the said :pawl is free to rotate :therebetween about said pivot bolt, and is placed sufliciently to one side of the wheel standard 32 that its cam surface '69 is away from theslide support members, .as illustrated in Figures 2 and l, but its lower end .31 will extend across at least part of the upper end of said wheel standard when said wheel standard is lowered sufficiently to permit said pawl .to hang vfreely.

Said wheel fork 33 .rotatably supports :a wheel M, which may be or any convenientconventional type upon the shaft 48. The bracket 1:6 maybe -removablyand adjustably attached to the chassis iii in an convenient way, foriexazmple, by means lof a pairof 1) -bolts 49 whichloop around a longitudinal member. 59 of said chassis and extend through suitable openings in the 'plates 28 and 2!, as illustrated in Figure 3.

Figures 5 and 6 illustrate an alternate bracket 53 and alternate cammed pawl54'suited to heavier duty than the bracket l6 and cammed pawl '33..

Said cammed pawl 54 is provided with a hook 55 adjacent to its upper'end and such end :is rotatably-supported upon said slide support members 55 and 5! (corresponding to slide support members 22 and 23 in the Figures 1 to 4 inclusive) by means of the pivot bolt 58. Said hook 55 may engage the wheel standard 59 either within the stop notch 6!] or at the end -6I thereof, as shown in Figures 5 and 6, respectively.

The central plates 52 and 6-3 of said alternate bracket 53 may be substantially the same as the 5. central plates and 2| of the bracket l6 except that the vertical groove 64 in the plate 62 is wider than the wheel standard 59 and therefore necessitates a guide block shim 65, which may be held in position by any suitable means such as the rivets 69. The reciprocable motion of the wheel standard 59 is guided and limited by means of the slidable association between the guide slots 56 and 61 in the slide support members 55 and 51, respectively, and the bolt 68 which is received through a suitable opening in said wheel standard 59 adjacent to the end 6| thereof.

In operation, the tool lift I5 is first secured to a longitudinal member of said chassis, as aforesaid, by means of the U-bolts 49 and appropriate lateral adjustment of said bracket H3 is made with respect to said chassis. Said stop block 45 shown in Figure 4 may be adjustably positioned on the wheel standard 3?) as required if it is desired to limit the depth to which the said tool l3 extends into the ground when the said tractorcultivator is being operated. The said wheel standard is free to move reciprocably as aforesaid, vertically with respect to the chassis ill of the said tractor-cultivator, within the limits imposed by the stop block 45 at the one end and the upper ends of guide slots and 28 at the other end.

If it is desired to suspend the cultivating tool l3 in a position of non-engagement with the ground, the handle bars M are raised, thereby lifting the chassis l0 and tool lift bracket H5 attached thereto until the relative downward motion of the wheel standard 30 effects an entry into the stop notch 36 by the free extremity 31 of the cammed pawl 38. If the said handle bars I are then released, the said cam extremity 31 will slide into secure, positive engagement with said stop notch 36. In such position, said tool l3 will be held above the ground, indicated in phantom at I! in Figure 1.

It will be noted that the pawl 38 is so constructed and suspended that its extremity 3'! will bear against that edge of said wheel standard 35 containing the stop notch 36. The said engagement of said notch 36 by said extremity 31 thereby becomes automatic when a downward motion of said wheel standard relative to the slide support members is effected.

If it then becomes desirable to return said tool [3 to a position of engagement with the ground, said handle bars 14 are again raised, thereby lifting said chassis l0 and said tool lift bracket l6, until the said wheel standard 30 drops below the point of engagement thereof with the lower end 31 of said pawl 38. Said pawl then swings across the inclined top 4| of said wheel standard 3! into a position of equilibrium, approximately as shown in Figure 4. If the handle bars are then lowered, the chassis Ill, hence the bracket it, moves downwardly thereby effecting a relative upward movement of the wheel standard until the said inclined top H engages the cam surface 40 of said pawl 38.

The inclination of said top 4! is designed to cooperate with said cam surface 4!! in producing a rotation of said pawl 38, shown as counterclockwise about its supporting bolt 39 in Figure 4, as said wheel standard moves relatively upwardly. Such rotation continues until the pawl is pushed over the top of its point of pivotal support whereupon it further continues by gravity until it again contacts the said wheel standard, as shown in Figure 2, whereupon it is ready to repeat the cycle. The wheel standard is then free to move upwardly until said bolt 35, attached to said upper extremity thereof, engages the upper ends of said guide slots 25 and 28, or until the stop block 45 engages the bottom of said bracket it if such stop block is used. This completes an operating cycle of said tool lift, by means of which and during which the said tool l3 was first suspended inoperatively and was then returned as desired to a position permitting engagement with the ground, none of which required disengagement of the operators hands from the cultivator handles.

The operation of a tool lift, illustrated in Figures 5 and 6, is identical in substance to the operation of the tool lift described above and appearing in Figures 1 through 4. However, the hook 55 on said pawl 54 provides for the positive engagement of said pawl with the wheel standard 59 at two different positions instead of one. Such positions comprises the stop notch 69, as shown in Figure 5, and the top SI of said wheel standard 59, as shown in Figure 6.

The manner in which said top 6| of said wheel standard 59 engages said pawl. 54 and urges it to rotate or recocl: itself automatically is substantially the same as described hereinbefore with respect to the wheel standard 30 and the pawl 38.

It will be observed, especially where the smaller tractor-cultivator is involved, that while said tool I3 is engaging the ground, the tool lift may often support no weight, but will be free to reciprocate within said bracket as the wheel 41 continually adjusts itself to the terrain and the motion of the tractor, and while the cammed pawl remains in a cocked position. For larger machines, where it is desired that the wheel 41 support the weight of the rear end of the machine during the cultivating operations :as well 7 as in t rning operations, the stop block 45 on the wheel standard 3!; and the modified bracket 53 and pawl 54 offer alternative means, by which said tool lift can be altered, within the scope of the invention, to effect such purposes.

Although the above mentioned drawings and description apply to a particular, preferred embodiment of the invention, it is not my intention, implied or otherwise, to eliminate other variations or modifications which do not depart from the scope of the invention unless specifically stated to the contrary in the hereinafter appended claims.

I claim:

1. An agricultural implement having a frame movable toward and away from the ground and including means mounting a tool thereon for movement with said frame between operative and inoperative position, and having also means carried by said frame for supporting such tool in either operative or inoperative position with reference to the ground. said means comprising: a wheel supported by wheel-supporting means slidably mounted on said frame; pawl means supported upon said frame and cooperating with said wheel-supporting means for holding said tool in inoperative position with respect to the ground, said pawl having a cam surface and being pivotally suspended so that said cam surface will. when said pawl is unobstructed. be engageable by an upper portion of said wheel supporting means movable toward and away therefrom for substantially complete rotation of said pawl about its pivot point as the tool is moved from inoperative to operative position.

2. An agricultural implement having a frame amass-1c 7 portion :movabl-e toward "(and away from the ground and including means mounting a :tool rhereonffor movement with :said'frame from'oper- :a'tive to inoperative position, and having also means carried by said frame :for supporting such tool in either operative or inoperative position with reference 'to the ground, said means comprising: a "wheel supported by means including avertically reciprocable bar -having a notch therein; pawl means connected to the tool supporting means and enterable'into said notch in one position of the tool with respect 'to the ground, said 7 pawl :oe'ing :supported for pivotal movement in a splane'parallelto the line of reciprocation of said bar, having a rammed surface on its one edge,

and 'so supported that when said :bar is-in its lowermost reciprooable "position the cam surface remote from :the pivoted end of :said pawl will at least in part Qbstantlally oppose the upper end of said :oar, the curvature ofssaidcam surface lacing such that, as said :bar is moved upward relative to said par-i1, it will rotate said pawl overzthe top of its point of pivotal support, where- :by :it will return by giazity'therefrom into a position against said bar 'free from engagement with said notch and means limiting the upward movement 40f relative to said loam.

3. An agricultural implement having a frame portion movable toward and away from the ground and including imeans .rnounti-ng a tool thereon for .znovementwith said :f-ramefrom operative to inoperative position, and having also means carried by said frame for supporting such tool in either operative or inoperative position with reference to the ground, said Ineans comprising: a wheel supported :by means including a vertically reciprocablebar her-ling a notch ther in; pawl means connected to the toolsupporting means and enterablie nto said notch in one position of the tool with respect to the ground, said pawl :being supported. .ior pivotal movement in a plane parallel to the line of reciprocation of said bar, having a carnrned surface on its one edge, and so supported that when said bar is in its lowermost reciprocabie position the cam surface remote from the pivoted end of said pawl will at least in part substantially oppose the upper end-of said bar, the curvature of said cam surface being such that, as said bar is moved upward relative to said pawl, it will rotate said pawl over the top-of its point of pivotal support, whereby it will return by gravity therefrom into a position against said bar free from engagement with said notch means located on said bar, and cooperating with means affixed to said frame for limiting the upward movement of said bar rela tiv-e-tosaid cam.

4. An agricultural implement having a frame portion movable toward and away from the ground and including means mounting a tool thereon for movement with said frame from operative to inoperative position, and having also means carried by said frame for supporting such tool in either operative or inoperative position reference to the ground, said means comprising: a wheel supported by means including a vertically reciprocable bar having a notch therein; pawl means connected to the tool supporting means and enterable into said notch in one position of the tool with respect to the ground, said pawl being supported for pivotal movement in a plane parallel to the line of reciprocation of said bar, having a cammed surface -on its one edge, and so supported that when said bar is in its lowermost reciprocable position the cam over the top of its point :of pivotal support, the

upper end of :said ibar be'ing contoured to cooperate with the oam surface :of said pawl, whereby :it will return by gravity therefrom into a position against said bar free "from engagement with said :notch; and means limiting the upward movement of said bar'rela'tive to said cam.

5. An agricultural implement having a frame portion movable toward and away from tlre ground and including means mounting a tool thereon for movement with said frame from :op erative to inoperative position, and having also :means carried by said frame for supporting suc'h tool in either operative or inoperative position with "reference to the ground, said means comprising: a pair of central plates ad justably affixed to said frame and defining a guideway therebetween, and vertically slotted, spaced -'gu-ide means extending above said plates :at least partially defining .a continuation of said guldeway; a wheel supported upon a vertically reciprocable bar received within saidguideway and means associated with said bar extending through the slotted-portions :of said guide means; pawl receiving means associated with said bar; a pawl pivotally supported between said spaced guide means and suspended so that its "lower end is 7 ciprocable position of said bar into cooperation with a portion of said Ebar, the curvature of said cam surface being such that as said ibar'is moved upward relative to said pawl it will rotate said pawl over the top of its point of pivotal support, whereby it will return by gravity therefrom into a position against said bar free from engagement with said notch limiting the upward movement of said bar relative to'said cam. V

6. An agricultural "implement having a' frame portion movable toward and away from the ground and inoluding means mounting a tool thereon for movement with said frame from op erative to inoperative position, and having also means carried by said frame for supporting such tool in, either operative or inoperative position with reference to the ground, said means' com prising: a pair of central "pl-ates adjustably af fixed to said frame and defining a guideway therebetween, and vertically slotted, spaced guide means extending above said plates at least partia'lly defining a continuation of said guideway; a wheel supported upon a vertically reoiprocable bar received'within said guideway and means associated with said bar extending through the slotted portions of said guide means pawl roceiving means associated with said bar; a pawl pivotally supported between sa'idspaced guide means having its center line constituting an and suspended so that its "lower end is urged by gravity against said bar and into operative cooperation with said pawl receiving means in one reciprocable position of said bar with respect to said pawl, said pawl having a cam surface of progressively increasing radius from the pivoted end to at least near the free end thereof mow able by gravity in another reciprocable position of said bar into cooperation with -a portion of said bar, the curvature of said cam surface being such that as said bar is moved upward relative to said pawl it will rotate said pawl over the top of its point of pivotal support, whereby it will return by gravity therefrom into a position against said bar free from engagement with said notch and means located on said bar and cooperating with means affixed to said frame for limiting the upward movement of said bar relative to said cam.

7. In an agricultural implement having a frame movable toward and away from the ground, said frame having means supporting a tool thereon for movement therewith, the improvement comprising: wheel support means slidably mounted on said frame and a wheel rotatably supported upon said support means; a pawl, and means pivotally supporting said pawl on said frame, said pawl being cooperable with said support means for holding said tool in a raised position, and said pawl having a cammed edge engageable by the upper end of said support means for rotating said pawl about its pivot point and thereby releasing said tool from said raised position.

8. In an agricultural implement having a frame vertically movable toward and away from the ground, said frame having means supporting a tool thereon for movement of said tool therewith between operative and inoperative positions of said tool, the improvement comprising: a bar vertically reciprocably supported upon said frame, said bar having a notch therein near the upper end thereof; means limiting the upward and downward reoiprocable movement of said bar with respect to said frame; a wheel rotatably supported upon the lower end of said bar; a pawl and means pivotally supporting said pawl near one end thereof upon said frame adjacent to the upper end of said bar and substantially Within a plane parallel therewith, said pawl being cooperable with said notch for holding said tool in the inoperative position, and said pawl having a oammed edge engageable by the upper end of said bar as said frame is first raised and then lowered with respect to said bar, said ca'mmed edge being so curved that said pawl is completely rotated around its pivot point by the upper end of said bar in cooperation with gravity as said frame is lowered, thereby permitting lowering said tool into operative position.

FRED N. SHARP.

file of this patent:

UNITED STATES PATENTS Name Date Towle May 3, 1921 Number 

